The present invention generally relates to power hand tools, and more particularly, to power reciprocating tools.
Reciprocating tools that are motor driven, such as saber saws, reciprocating saws and the like are usually driven by electric motors that have a rotating output shaft. The rotating motion is translated into reciprocating motion for moving a saw blade or the like in a reciprocating manner. In some reciprocating saws, the saw reciprocates in an orbital or non-linear motion, as opposed to a straight line motion. The orbital motion is commonly characterized by a forward (i.e., opposite the cutting direction) motion of the saw blade as the saw blade is extended away from the saw on the cutting stroke, and a corresponding rearward (i.e., in the cutting direction) motion of the saw blade as the saw blade is being retracted toward the saw on the return stroke. The result is a circuitous, or orbital, path of the blade. Such orbital motion is believed to improve the speed at which the saw cuts a workpiece by driving the saw blade into the workpiece during the cutting stroke and withdrawing the saw blade from the workpiece during the return stroke.
In some instances, it is desirable to toggle orbit action off. For example, when performing a precise cut with orbit action on, one may experience bouncing of the saw blade. In this case, one technique known in the art is to turn orbit action off using a mechanical switch. However, this often results in a slower cutting process after the cut is started.
An alternative technique is to leave orbit action on and include a variable speed control switch. For instance, when cutting wood, plaster board or soft metal in a precise manner, one can start a cut at a very low speed, then once the cut is precisely located, go to full speed to complete the cut. As such, the concern that the orbit function will cause the blade to bounce off the material being cut is negated by the variable speed control. However, variable-speed control is only as consistent as one's ability to depress the trigger slightly while the saw bites into the material being cut. Additionally, there are some instances when it is desirable to have the orbit action effects completely negated such as when cutting hard metals.